org.apache.pulsar.functions.windowing.TriggerPolicy Maven / Gradle / Ivy
/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.pulsar.functions.windowing;
/**
* Triggers the window calculations based on the policy.
*
* @param the type of the event that is tracked
* @param the type of state that is used
*/
public interface TriggerPolicy {
/**
* Tracks the event and could use this to invoke the trigger.
*
* @param event the input event
*/
void track(Event event);
/**
* resets the trigger policy.
*/
void reset();
/**
* Starts the trigger policy. This can be used
* during recovery to start the triggers after
* recovery is complete.
*/
void start();
/**
* Any clean up could be handled here.
*/
void shutdown();
/**
* Return runtime state to be checkpointed by the framework for restoring the trigger policy
* in case of failures.
*
* @return the state
*/
S getState();
/**
* Restore the trigger policy from the state that was earlier checkpointed by the framework.
*
* @param state the state
*/
void restoreState(S state);
}